1. Field of the Invention
The present invention relates to devices used with ultrasonic cutting devices used in the removal of tissue and/or matter from a living body, and more particularly, to an improved infiltration cannula which is capable of infusing tissue with medication.
2. Description of Related Art
Probes or scalpels for the fragmentation and removal of materials, tissue and fluids from living beings are known to the art. For example, U.S. Pat. No. 2,227,727, issued Jan. 7, 1941 to Vincent Leggiardro, discloses an apparatus for fragmenting naturally formed stones, such as kidney stones, and the like, utilizing a high speed reciprocating rod which may have a blunt end, a sharp or chisel point, a cutting blade, or combination thereof, such as a cutting blade having a blunt end.
A particular arrangement in an ultrasonically vibrated surgical tool using an irrigation fluid and an anti-coagulant is disclosed in U.S. Pat. No. 4,493,694, issued Jan. 15, 1985, to David G. Wuchinich, utilizes a hollow tool having a suction passage and at least one pre-aspirating orifice in the wall of the tool, and a plastic sleeve concentrically spaced about the tool for admitting fluid from a supply into the space between the tool and passing substantially all of the fluid through the pre-aspirating orifice.
In the application of ultrasonics to liposuction, instruments of varying configurations recently have been proposed. In U.S. Pat. No. 5,236,414, issued Aug. 17, 1993 to Katsuya Takasu, a tubular body defining a suction passage has an opening in its front lower end, and an outer tube having a corresponding opening, by means of which fat tissue is crushed and/or emulsified due to the vibration of the front end of the tubular body and is then aspirated. In U.S. Pat. No. 5,514,086, issued May 7, 1996, to Parisi et al., an ultrasonically vibrated hollow probe has a port in its surface for aspiration and a tip substantially formed of plastic.
While the use of ultrasonic probes for liposuction has proven effective, it is fraught with discomfort and certain health risks. For example, the ultrasonic removal of tissue may cause pain and swelling. Excessive bleeding may also result from liposuction.
Epinephrine has been found to be effective in reducing bleeding during liposuction. Similarly, Lidocane has been found effective in reducing pain. However, it is often difficult to effectively introduce these drugs into fat tissue, in advance of liposuction.
While prior art devices have relied upon localized injection methods, the process of localized injection may result in a great deal of discomfort. Accordingly, a need exists for a device for infiltrating fat with medication that is less painful to administer and which reduces trauma to tissue.
An infiltration cannula is provided. The infiltration cannula includes an axially elongated tube having a circular cross-section, a proximal end portion adapted to receive a treatment fluid and a distal end portion with a plurality of apertures disposed in a transverse sidewall of the distal end portion of the elongated tube for dispensing the treatment fluid. The cannula also includes a TEFLON polytetrafluroethylene, PTFE, etc. coating disposed over and outer surface of the elongated member.